Here's how to buy your own pocket-sized copy of the US Constitution

That's about what it costs to own a pocket-sized copy of the U.S. Constitution — like the one Khizr Khan waved in a stinging rebuke of Republican president nominee Donald Trump on Thursday at the Democratic National Convention.

Khan, the father of Muslim soldier Army Capt. Humayun Khan, who was killed in Iraq in 2004, rejected Trump's Islamophobic rhetoric and the candidate's calls for banning Muslim immigration to the U.S., as an anti-terrorism strategy.

"Donald Trump, you are asking Americans to trust you with their future," Kahn said at a crescendo of his remarks at in Philadelphia. "Let me ask you, have you even read the United States Constitution? I will gladly lend you my copy."

Khan cited language in the Constitution that establishes principles of equality and discourages discrimination.

The first section of the 14th Amendment to the U.S. Constitution spells out what is known as the equal protection clause:

All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the state wherein they reside. No state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any state deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.

The National Constitution Center, a museum in Philadelphia, sells pocket-sized constitutions at a price of $2.50. They can also be ordered online.

Oak Hill Publishing Company has a pocket-sized constitution online at PocketConstitution.org, at a price of $3.95.